Provided herein is a semiconductor device. The semiconductor device may include conductive layers each including a line, and a pad which is coupled with the line and has a thickness greater than that of the line, the conductive layers being stacked such that the pads are exposed; insulating layers interposed between the conductive layers; first spacers each of which is interposed between the pad of the corresponding upper conductive layer and the pad of the corresponding low conductive layer; and second spacers covering the respective first spacers.